Can you help identify this phenomena? The below video shows a flash of currently unknown origin observed at Mauna Kea Observatory the morning of 2011 March 22. Here is a moving gif of it (note the time stamps):

flashsphere_kpno.gif

Here is an email that APOD received describing it:

My name is Ichi Tanaka, a Support Astrnomer of Subuaru Telescope, Hawaii.

On the early morning of 22 March we, Subaru Telescope observers on the summit of Mauna Kea, noticed that there is a huge halo of lightabove the eastern horizon. It was slowly expanding to over 45 degrees in 5 minutes or more.

The event was captured by the Subaru Catwalk Night Camera and also byCHFT's NNW webcam. The animated gif movie of the Subaru webcam is attached. I also contacted Kanoa Withington in CFHT, and they made a quite nice movie of the event. The link is below.

We have absolutely no idea about the nature of this. It appears that the event happened not on the Summit area, butmuch farther away, according to the comparison of the two videos. This means that the size of the light halo is quite large.After some discussion, we decided to send this to APOD, in the hopes that APOD readers can help us to understand the nature of this event.

It seems to me that this is an excellent case for opportunity "Citizen Science" in that I bet the alert readers of APOD and the Asterisk can indeed figure this out. Please have at it!

- RJN

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I'm curious how one envisions fuel discharging with a sphere that moves along with its center... wouldn't that produce more of a wake shape or possible a spiral? In order to retain the spherical/circular form, would not the object have to be moving relatively away from or toward the observer? The halo appears to be beyond the cloud bank, making it certainly above the atmosphere... could it be an exploding near earth approaching asteroid/comet?

Venting sounds reasonable. I assume that the time is local time. What direction was the origin of the flash? A satellite tracker should be able to found that can track backwards in time. What was in that direction at that time? Is their a record of the satellite in question venting or some other activity and what direction was it moving relative to the camera?

It does look like an explosion/rapid de-gassing of a vehicle in low earth orbit (tho east to west orbits are quite unusual), backlit by the sun . The 8 minutes or so seen for propagation of the "wave" would seem to rule out truly violent, nuclear-bomb style, cause, as such ionizing proceeds at light speed. I'm curious why the stars move as expected in the Subaru film, but most of them (!) don't move at all in the other, higher-res CFHT, while the ground and lights there are also stable in the frame. Some few fuzzy "stars" do move upward in the right direction, but the many colored ones don't. What gives there?

<<The Air Force plans a second hypersonic flight test next week of its X-51A Waverider aircraft, hoping that some improvements will avoid a problem that cut short last year’s first flight. The date of the flight over the Pacific Ocean is March 22, if plans don’t change before then, said Charlie Brink, X-51A program manager with the Air Force Research Laboratory’s propulsion directorate at Wright-Patterson Air Force Base. The 14-foot-long aircraft is called the Waverider because it rides its own shockwave.

Once again, a B-52 from Edwards Air Force Base, Calif., is to carry the Waverider aloft under a wing and release the aircraft at about 50,000 feet over the Pacific Ocean. A solid rocket booster will then accelerate the Waverider before its air-breathing scramjet (short for supersonic combustion ramjet) engine kicks in for what the Air Force hopes will be a four-minute flight reaching the speed of Mach 6.

The initial May 2010 flight had to be terminated after slightly more than two minutes, when the Waverider had reached Mach 5, on the way to a hoped-for Mach 6. The military controller intentionally sent the Waverider crashing into the Pacific after controllers lost contact with the high-speed vehicle, Brink said. A failed seal at a nozzle caused hot gases to build up inside the Waverider, rather than go out the back of the nozzle, Brink said. Engineers have made improvements they hope will avoid a repeat, he said.

It is the second of four test flights for the $246.5 million Waverider program, begun in December 2003. It is being done to demonstrate technology the Air Force hopes can eventually be used for more efficient transport of payloads into orbit.

The flights are all to end with crashing the Waveriders into the Pacific. The Air Force determined that, at the speed they fly, the Waveriders would sink before ships could get to where the aircraft hit the water, Brink said. “Of the existing X-51s, there is no plan to modify them to be recoverable,” he said.>>

I'd also go with the fuel/gas venting scenario. I've seen them before, and seen images, and although I've never seen one as spherical as this, they look otherwise very similar. The center of the expanding region seems to be tracking at about the right speed for a LEO satellite, as well.

Cassiopeia and Triangulum are apparent in the background stars, so we are looking low to the NE.

Here is what I observe.1) My first guess was a volcanic vent sending a up a plume of gas from the ocean floor and picking up ambient light. Hovever the plume is moving counter to the prevailing winds, so it appears to be outside the atmosphere. (note the movement of the clouds.)2) Aditionally, the centroid of the plume rises faster than the rise of the background stars but just about on the same path. If the view is East then it is moving counter to earth's rotation along the equator.

Conclusion: Something may have vaporised that was in an equatorial orbit counter to earth's rotation.

Sorry, I failed to sign the above comment. As far as what vaporized... perhaps a small cometary fragment hitting the outer atmosphere and falling towards the observers. We see it get closer, expand and dissapate.

It would appear that this mystery flash being spherical is happening in the vacuum space or near vacuum of very high altitude in the atmosphere. It reminds me of barium rocket releases used to probe the magnetic fields of the ionosphere having witnessed a few of these releases in the 70's. I suspect something gasious entered the earths upper atmosphere, a low density frozen snowball and vaporized and turned into a rapidly expanding spherical cloud of gas and plasma to entirely dissipate. It was a plasma because it emitted light and at the boundary of the spherical shell that light is the brightest where it is concentrated by angle of perspective. This event should have also produced a radio signal which may have been recorded elsewhere and perhaps on radar.

Following on from my earlier idea, given that it takes about 4 minutes from start to finish, and that the centre of the circle is close to the horizon, it could easily be coming from a car driving up the mountain road with a light shining up at the camera.

Matt Kenworthy wrote:Following on from my earlier idea, given that it takes about 4 minutes from start to finish, and that the center of the circle is close to the horizon, it could easily be coming from a car driving up the mountain road with a light shining up at the camera.

Interesting idea, Matt. But more than one camera on Mauna Kea saw it. (See the movie link in the initial post, for example.) If true, though, this transient should not have been seen from the neighboring island on Haleakala. Can someone check to see if it was seen from there as well?

Also, cars drive up to Mauna Kea all of the time, sometimes with their headlights on. For this to work, there must have been some sort of unusual reflection layer, like a cloud of fog that permeated the local air, or the air at some level.

A scheduled launch from Vandenberg AFB of a Minuteman3 around this same time may offer some explanation basis... The rocket was headed for re-entry at the Kwajalein Atoll so direction and time might fit. I have seen similar bubbles at dusk from launches in Florida back in the 60s but was told then that they were some kind of weather testing.

The gif says 06/22 also, but Hawaii is only 2 hours earlier than California, unless the time stamps are still "standard time". If so, the times align quite well with the launch time stated in the VAFB PR.

Know the quiet place within your heart and touch the rainbow of possibility; be alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor

by bystander » Fri Jun 24, 2011 8:26 pmThe gif says 06/22 also, but Hawaii is only 2 hours earlier than California, unless the time stamps are still "standard time". If so, the times align quite well with the launch time stated in the VAFB PR.

At this time of year there is a 3 hour difference between California and Hawaii.

The videos are misleading unless you carefully check the time stamps. We're talking 6 minutes for it to move from the horizon to out of focus. I think that rules out venting because it's moving much too slowly. Whatever it is, is somehow managing to reflect light; and more so on its circumference.

To me it looks like the moon (or at least a ghost version of the moon). My guess is that we're seeing a dense mist which is reflecting the moon, in the same way we see a reflection on a lake. Unlike water, a dense mist would give it an opaque/transparent effect and could also explain the movement. The speed would be about right too.